"It's amazing that any pharmaceutical reps call on me at all," he said.
He's been fighting a one-man battle against a widespread medical practice. It puts profit ahead of health and costs you hundreds of millions of dollars, CBS News correspondent Sharyl Attkisson reports.
"I may be just a big pain in the ass," he said.
It started when he caught Memorial Hospital in New Orleans doing something very odd.
Every time he prescribed Zantac, the hospital changed it to Pepcid. Both are acid blockers than can prevent dangerous internal bleeding.
"I said, 'why is it I'm ordering one drug and a totally different drug is being given?'" LaCorte said. "And I was told 'therapeutic interchange.'"
Therapeutic interchange meant the hospital was switching virtually all antacid prescriptions to Pepcid. And it wasn't a meaningless change.
While LaCorte says Pepcid is a good drug, it was given in doses that were too strong for some patients, making them very sick. One even went into a coma.
When he tried to find out why so many were given Pepcid, he discovered Memorial Hospital had made what's called a "market share" deal with Merck, the maker of the drug. As long as 80 percent of patients were on Pepcid, Merck gave the hospital a deep discount.
The hospital's task was to get almost all of the patients who needed that type of drug on the Merck brand drug, according to LaCorte.
LaCorte complained to everyone he could think of … without result.
Finally, he got the feds involved - by proving taxpayers were being defrauded. It turns out the Pepcid cost twice as much as Zantac, and since many patients were on Medicaid or Medicare, taxpayers covered the extra cost.
The fight took 12 long years, but Merck recently agreed to pay back taxpayers $650 million for deals to get hospitals nationwide to favor not only Pepcid, but also Merck drugs Zocor and Vioxx.
Under U.S. law for whistleblowers, LaCorte will get a sizable payment from the recovered money.
"This is a widespread practice with multiple medications," he said. "This is business-as-usual for the hospitals and drug companies in the United States of America today."
LaCorte says taking them on is tougher than fighting City Hall.
But he's just the doctor with the bedside manner to do it.